Seems too far fetched to me. Becoming a completely degraded person to blackmail or punish somebody that you simply don't like? Isn't it easier for a prize wife to get a good lawyer and go for a decently rewarding divorce?From what she's said: blackmail. Once she has some influential friends outside Elias' control, she plans to leverage the dirt she's picked up on other people over the years (plus her high charisma) to get her what she needs. She may end up with less in terns in total dollars in her pocket than she had with Elias, but she'll accept that because she'll have far more say on how to use it.
And it's worth noting that her plan could work... *IF* everything goes well. The fact she's degrading herself in front of people who can't call her out on that in public is immaterial to her as long as they give her the contacts she needs; it's not like being sexually degraded is repulsive to her. Elias will no doubt learn about this eventually, but if Felicia has her own network by then it won't matter to her.
Of course, we in the audience have already learned that Felicia's plan is doomed, and it was always going to be something of a longshot. But Felicia was desperate enough and/or overconfident enough to assume she could make it work, so she tossed her hat into the ring. That arguably makes her foolish (and I have indeed argued that), but people act in foolish ways all the time.
And about degradation, one thing is to love sex and enjoy it e.g. making young boys like the MC your sex toys or even holding wild sex orgies at your mansion. The other thing is being spunked on by a dozen of old assholes to become a disgusting trash can. I'm not that good at human deviation psychology but for me it doesn't look like what a "sex sage" is.
That's basically my disappointment that Felicia's impression of a stunning, cunning and manipulative sex guru was quickly replaced by an image of a rather stupid and primitive whore driven by her basic animal instincts.